The main difference between SPF and UPF is that SPF only provides protection from UVB rays, while UPF provides protection from both UVB and UVA, the two main types of ultraviolet rays, which cause skin cancer. While UVB rays cause sunburn, UVA rays penetrate deep into the skin and cause premature skin-aging and wrinkle formation.
SPF (Sun Protection Factor) and UPF (Ultraviolet Protection Factor) are two measures of sun protection. But SPF is different from UPF. SPF is a standard that measures the effectiveness of sunscreens, while UPF is a rating system for fabrics.
Key Areas Covered
1. What is SPF
– Definition, Features
2. What is UPF
– Definition, Features
3. Difference Between SPF and UPF
– Comparison of Key Differences
Key Terms
SPF, Sun Protection Factor, UPF, Ultraviolet Protection Factor
What is SPF
SPF or Sun Protection Factor is a measure of protection from exposure to ultraviolet rays. It indicates how much UV radiation is needed to produce sunburn on the skin (skin that has been applied sunscreen) relative to the amount of UV radiation needed to produce sunburn on unprotected skin. When the value of SPF increases, sunburn protection also increases.
Some people assume that SPF indicates the time of solar exposure. For instance, they believe that if they usually get sunburn in one hour, then a sunscreen with SPF 15 would allow them to stay in the sun for 15 hours without getting any sunburn. But this assumption is not correct. SPF is not directly related to the time of solar exposure. SPF is actually related to the amount of solar energy or UV radiation. Although the amount of solar energy affects solar exposure time, there are also other factors affecting the amount of solar energy. These include factors like the intensity of solar energy, skin type, amount of sunscreen you apply, geographical location, and frequency of reapplication.
SPF 15 blocks 93% of UVB rays, while SPF 30 blocks 97% of UVB rays. SPF 50, on the other hand, blocks 98% of UVB rays. Most dermatologists recommend using an SPF of at least 30.
What is UPF
UPF or Ultraviolet Protection Factor is a measure of how much UV radiation a fabric allows to reach the skin. This UV radiation includes both UVB and UVA. It represents the ratio of sunburn-causing UV measured with and without the protection of the fabric. For instance, a fabric with UPF 30 means that if 30 units of UV fall on the fabric, only 1 unit passes through to the skin. Therefore, a fabric with UPF 30 that blocks 29 out of 30 units of UV can block 96.7%.
We can describe UPF as a textile rating system to rate apparel. This is a relatively new rating system. Moreover, it’s important to know that, unlike SPF, UPF is not directly applied to the skin.
Difference Between SPF and UPF
Definition
SPF or Sun Protection Factor is a measure of protection from exposure to ultraviolet rays, while UPF or Ultraviolet Protection Factor is a measure of how much UV radiation a fabric allows to reach the skin.
Nature
Moreover, SPF is a standard that measures the effectiveness of sunscreens, while UPF is a rating system for fabrics.
Application
SPF is directly applied to the skin, but UPF is not directly applied to the skin.
UVB vs UVA
UPF provides protection from both UVB and UVA, whereas SPF only provides protection from UVB.
Conclusion
SPF and UPF are two measures of sun protection. But SPF is not the same as UPF. SPF is a standard that measures the effectiveness of sunscreens, while UPF is a rating system for fabrics. Moreover, SPF only provides protection from UVB, while UPF provides protection from both UVB and UVA. Thus, this is the main difference between SPF and UPF.
Reference:
1. “Sun Protective Clothing.” The Skin Cancer Foundation.
2. “Sun Protection Factor (SPF).” U.S. Food and Drug Administration, FDA.
Image Courtesy:
1. “Brunette putting sunscreen on her shoulder” By Skeyndor (Public Domain) via Flickr
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